This invention relates to an information reading system using a television camera to read out information expressed, for example, by the array of bar codes printed on bar coded labels corresponding to price tags affixed to goods.
In order to automatically read out bar coded labels, it has been already proposed to pick up each bar coded labels affixed to goods by a television camera and process the resulting video signal from the television camera. In this case the television camera has normally picked up the bar coded label while a raster formed of scanning lines or beams produced therein is rotated at a predetermined speed of rotation for the purpose of preventing some bar codes of the array from failing to be picked up by the camera. Under these circumstances, a video signal from a field thus rotated has been affected by uneven after-images left on the television camera due to that field scanned immediately prior to the rotation thus resulting in the occurence of a spurious video signal. This is because a gap is present between each pair of adjacent scanning lines or beams. Such a spurious video signal has caused an error in reading out information.
Accordingly it is an object of the present invention to provide a new and improved information reading system decreased in reading error resulting from after-images left on a television camera involved.